X-ray diagnosis apparatuses are present, which use X-rays for diagnosis of a subject. In some cases, an X-ray diagnosis apparatus is used in an examination room during a medical procedure, and a procedure performer sometimes operates the X-ray diagnosis apparatus with a foot switch. As a foot switch for such an X-ray diagnosis apparatus, a wireless foot switch has been proposed, which transmits signals to the X-ray diagnosis apparatus by radio. A wireless foot switch is advantageous in that the installation position thereof can be easily changed according to the move of the procedure performer.
Because of the need to use a built-in battery for putting the wireless foot switch into operation, however, a wireless foot switch is inconvenient for its limited operating time. Although using a larger built-in battery may be effective in extending the operating time, a larger built-in battery increases the weight of a wireless foot switch and makes the wireless foot switch difficult to move.